+ nf_rec->ip_tos = expired->flow.nw_tos;
+
+ /* NetFlow messages are limited to 30 records. */
+ if (ntohs(nf_hdr->count) >= 30) {
+ netflow_run(nf);
+ }
+}
+
+void
+netflow_expire(struct netflow *nf, struct netflow_flow *nf_flow,
+ struct ofexpired *expired)
+{
+ uint64_t pkt_delta = expired->packet_count - nf_flow->packet_count_off;
+ uint64_t byte_delta = expired->byte_count - nf_flow->byte_count_off;
+
+ nf_flow->last_expired += nf->active_timeout;
+
+ /* NetFlow only reports on IP packets and we should only report flows
+ * that actually have traffic. */
+ if (expired->flow.dl_type != htons(ETH_TYPE_IP) || pkt_delta == 0) {
+ return;
+ }
+
+ /* NetFlow v5 records are limited to 32-bit counters. If we've
+ * wrapped a counter, send as multiple records so we don't lose
+ * track of any traffic. We try to evenly distribute the packet and
+ * byte counters, so that the bytes-per-packet lengths don't look
+ * wonky across the records. */
+ while (byte_delta) {
+ int n_recs = (byte_delta + UINT32_MAX - 1) / UINT32_MAX;
+ uint32_t pkt_count = pkt_delta / n_recs;
+ uint32_t byte_count = byte_delta / n_recs;
+
+ gen_netflow_rec(nf, nf_flow, expired, pkt_count, byte_count);
+
+ pkt_delta -= pkt_count;
+ byte_delta -= byte_count;
+ }